Using expirationTime and childExpirationTime

Related pr facebook/react#13139

demo/package.json

@@ -17,9 +17,5 @@
     "webpack": "4.28.4",
     "webpack-cli": "3.2.1",
     "webpack-dev-server": "3.1.14"
-  },
-  "dependencies": {
-    "react": "16.8.0-alpha.1",
-    "react-dom": "16.8.0-alpha.1"
   }
 }

demo/yarn.lock

@@ -2796,7 +2796,7 @@ js-tokens@^3.0.0:
   version "3.0.2"
   resolved "https://registry.yarnpkg.com/js-tokens/-/js-tokens-3.0.2.tgz#9866df395102130e38f7f996bceb65443209c25b"
 
-"js-tokens@^3.0.0 || ^4.0.0", js-tokens@^4.0.0:
+js-tokens@^4.0.0:
   version "4.0.0"
   resolved "https://registry.yarnpkg.com/js-tokens/-/js-tokens-4.0.0.tgz#19203fb59991df98e3a287050d4647cdeaf32499"
   integrity sha512-RdJUflcE3cUzKiMqQgsCu06FPu9UdIJO0beYbPhHN4k6apgJtifcoCtT9bcxOpYBtpD2kCM6Sbzg4CausW/PKQ==
@@ -2927,13 +2927,6 @@ loose-envify@^1.0.0:
   dependencies:
     js-tokens "^3.0.0"
 
-loose-envify@^1.1.0, loose-envify@^1.3.1:
-  version "1.4.0"
-  resolved "https://registry.yarnpkg.com/loose-envify/-/loose-envify-1.4.0.tgz#71ee51fa7be4caec1a63839f7e682d8132d30caf"
-  integrity sha512-lyuxPGr/Wfhrlem2CL/UcnUc1zcqKAImBDzukY7Y5F/yQiNdko6+fRLevlw1HgMySw7f611UIY408EtxRSoK3Q==
-  dependencies:
-    js-tokens "^3.0.0 || ^4.0.0"
-
 lower-case@^1.1.1:
   version "1.1.4"
   resolved "https://registry.yarnpkg.com/lower-case/-/lower-case-1.1.4.tgz#9a2cabd1b9e8e0ae993a4bf7d5875c39c42e8eac"
@@ -3326,7 +3319,7 @@ number-is-nan@^1.0.0:
   version "1.0.1"
   resolved "https://registry.yarnpkg.com/number-is-nan/-/number-is-nan-1.0.1.tgz#097b602b53422a522c1afb8790318336941a011d"
 
-object-assign@^4.0.1, object-assign@^4.1.0, object-assign@^4.1.1:
+object-assign@^4.0.1, object-assign@^4.1.0:
   version "4.1.1"
   resolved "https://registry.yarnpkg.com/object-assign/-/object-assign-4.1.1.tgz#2109adc7965887cfc05cbbd442cac8bfbb360863"
 
@@ -3635,14 +3628,6 @@ promise-inflight@^1.0.1:
   resolved "https://registry.yarnpkg.com/promise-inflight/-/promise-inflight-1.0.1.tgz#98472870bf228132fcbdd868129bad12c3c029e3"
   integrity sha1-mEcocL8igTL8vdhoEputEsPAKeM=
 
-prop-types@^15.6.2:
-  version "15.6.2"
-  resolved "https://registry.yarnpkg.com/prop-types/-/prop-types-15.6.2.tgz#05d5ca77b4453e985d60fc7ff8c859094a497102"
-  integrity sha512-3pboPvLiWD7dkI3qf3KbUe6hKFKa52w+AE0VCqECtf+QHAKgOL37tTaNCnuX1nAAQ4ZhyP+kYVKf8rLmJ/feDQ==
-  dependencies:
-    loose-envify "^1.3.1"
-    object-assign "^4.1.1"
-
 proxy-addr@~2.0.4:
   version "2.0.4"
   resolved "https://registry.yarnpkg.com/proxy-addr/-/proxy-addr-2.0.4.tgz#ecfc733bf22ff8c6f407fa275327b9ab67e48b93"
@@ -3759,26 +3744,6 @@ rc@^1.2.7:
     minimist "^1.2.0"
     strip-json-comments "~2.0.1"
 
-react-dom@16.8.0-alpha.1:
-  version "16.8.0-alpha.1"
-  resolved "https://registry.yarnpkg.com/react-dom/-/react-dom-16.8.0-alpha.1.tgz#dab73b8354ba2e498e3127d18e29d4546cea889e"
-  integrity sha512-tZCUM8BpnwUHJmLnUWP9c3vVZxnCqYotj7s4tx7umojG6BKv745KIBtuPTzt0EI0q50GMLEpmT/CPQ8iA61TwQ==
-  dependencies:
-    loose-envify "^1.1.0"
-    object-assign "^4.1.1"
-    prop-types "^15.6.2"
-    scheduler "^0.13.0-alpha.1"
-
-react@16.8.0-alpha.1:
-  version "16.8.0-alpha.1"
-  resolved "https://registry.yarnpkg.com/react/-/react-16.8.0-alpha.1.tgz#c2b32689f3b466d3ce85a634dd9035f789d2cd97"
-  integrity sha512-vLwwnhM2dXrCsiQmcSxF2UdZVV5xsiXjK5Yetmy8dVqngJhQ3aw3YJhZN/YmyonxwdimH40wVqFQfsl4gSu2RA==
-  dependencies:
-    loose-envify "^1.1.0"
-    object-assign "^4.1.1"
-    prop-types "^15.6.2"
-    scheduler "^0.13.0-alpha.1"
-
 "readable-stream@1 || 2", readable-stream@^2.0.0, readable-stream@^2.0.4, readable-stream@^2.1.5, readable-stream@^2.2.2, readable-stream@~2.3.6:
   version "2.3.6"
   resolved "https://registry.yarnpkg.com/readable-stream/-/readable-stream-2.3.6.tgz#b11c27d88b8ff1fbe070643cf94b0c79ae1b0aaf"
@@ -4017,14 +3982,6 @@ sax@^1.2.4:
   resolved "https://registry.yarnpkg.com/sax/-/sax-1.2.4.tgz#2816234e2378bddc4e5354fab5caa895df7100d9"
   integrity sha512-NqVDv9TpANUjFm0N8uM5GxL36UgKi9/atZw+x7YFnQ8ckwFGKrl4xX4yWtrey3UJm5nP1kUbnYgLopqWNSRhWw==
 
-scheduler@^0.13.0-alpha.1:
-  version "0.13.0-alpha.1"
-  resolved "https://registry.yarnpkg.com/scheduler/-/scheduler-0.13.0-alpha.1.tgz#753977fb4fb35d8cdd559868a11e46b640955556"
-  integrity sha512-W0sH0848sVuPKg+I18vTYQyzVtA4X1lrVgSeXK6KnOPUltFdJcY5nkbTkjGUeS/E0x+eBsNYfSdhJtGjT95njw==
-  dependencies:
-    loose-envify "^1.1.0"
-    object-assign "^4.1.1"
-
 schema-utils@^0.4.4:
   version "0.4.7"
   resolved "https://registry.yarnpkg.com/schema-utils/-/schema-utils-0.4.7.tgz#ba74f597d2be2ea880131746ee17d0a093c68187"

src/ChildFiber.js

@@ -3,7 +3,7 @@ import {
   createFiberFromElement,
   createFiberFromText,
 } from "./Fiber";
-import { NoEffect, Deletion, Placement } from "./TypeOfSideEffect";
+import { Deletion, Placement } from "./TypeOfSideEffect";
 import { HostText } from "./TypeOfWork";
 import { REACT_ELEMENT_TYPE } from "./createElement";
 

src/Component.js

@@ -15,7 +15,7 @@ export class Component {
     scheduleWork(fiber, expirationTime);
   }
 
-  isReactComponent = {};
+  isReactComponent() {}
 }
 
 export const ReactInstanceMap = {

src/Fiber.js

@@ -9,6 +9,7 @@ import {
 } from "./TypeOfWork";
 import { REACT_ASYNC_MODE_TYPE, REACT_STRICT_MODE_TYPE } from "./createElement";
 import { AsyncMode, StrictMode } from "./TypeOfMode";
+import { NoWork } from "./FiberExpirationTime";
 
 export class FiberNode {
   constructor(tag, pendingProps, key, mode) {
@@ -31,18 +32,28 @@ export class FiberNode {
     this.memoizedState = null;
 
     this.mode = mode;
+
     // Effects
     this.effectTag = NoEffect;
     this.nextEffect = null;
     this.firstEffect = null;
     this.lastEffect = null;
+
+    this.expirationTime = NoWork;
+    this.childExpirationTime = NoWork;
+
     this.alternate = null;
   }
 }
 
 export function createWorkInProgress(current, pendingProps, expirationTime) {
   let workInProgress = current.alternate;
   if (workInProgress == null) {
+    // We use a double buffering pooling technique because we know that we'll
+    // only ever need at most two versions of a tree. We pool the "other" unused
+    // node that we're free to reuse. This is lazily created to avoid allocating
+    // extra objects for things that are never updated. It also allow us to
+    // reclaim the extra memory if needed.
     workInProgress = new FiberNode(
       current.tag,
       pendingProps,
@@ -55,21 +66,34 @@ export function createWorkInProgress(current, pendingProps, expirationTime) {
     workInProgress.alternate = current;
     current.alternate = workInProgress;
   } else {
+    workInProgress.pendingProps = pendingProps;
+
+    // We already have an alternate.
+    // Reset the effect tag.
     workInProgress.effectTag = NoEffect;
 
+    // The effect list is no longer valid.
     workInProgress.nextEffect = null;
     workInProgress.firstEffect = null;
     workInProgress.lastEffect = null;
   }
 
-  workInProgress.expirationTime = expirationTime;
-  workInProgress.pendingProps = pendingProps;
+  // Don't touching the subtree's expiration time, which has not changed.
+  workInProgress.childExpirationTime = current.childExpirationTime;
+  if (pendingProps !== current.pendingProps) {
+    // This fiber has new props.
+    workInProgress.expirationTime = expirationTime;
+  } else {
+    // This fiber's props have not changed.
+    workInProgress.expirationTime = current.expirationTime;
+  }
 
   workInProgress.child = current.child;
   workInProgress.memoizedProps = current.memoizedProps;
   workInProgress.memoizedState = current.memoizedState;
   workInProgress.updateQueue = current.updateQueue;
 
+  // These will be overridden during the parent's reconciliation
   workInProgress.sibling = current.sibling;
   workInProgress.index = current.index;
   workInProgress.ref = current.ref;